A middle class family used to be able to get by just fine on one income. I know...I grew up in just such a family. My father never went to college, but wound up in a management position that allowed us to afford a nice house on the water with a boat. Mom went to college but didn't need to work, so she stayed home until us kids were old enough, and then (after a few classes to get back up to speed) went back to work in health care. All three kids went to college, and nobody graduated with student loan debt.
Fast forward until today, and it would be difficult to replicate that sort of life with one income no matter which spouse was working.
It would be effectively impossible to replicate a 60s lifestyle--because our standards are much higher now than then. An awful lot of 60s level products are nowhere near modern standards.